1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly to task scheduling within user equipment for wireless communication systems.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provide higher data transfer speeds and capacity to associated UMTS networks. Long Term Evolution (LTE), also referred to as enhanced UTRA (E-UTRA) is a further successor technology standardized by the 3GPP.
Discontinuous Reception (DRX) is a power-saving feature in wireless technologies where a user equipment (UE) (e.g., including but not limited to a mobile phone, a smartphone, a laptop computer, a mobile device, etc.) monitors a subset of downlink channels over specified time intervals. The UE and its associated network may negotiate the specified time intervals during which data transfers relevant to the UE may occur. When the UE monitors the subset of downlink channels over the specified time intervals, the UE's receiver circuitry may be on. At other times, for example when the UE is not monitoring the downlink channels, the UE may shut down receiver circuitry to reduce current usage and increase battery life. The circuitry shut down can include but is not limited to radio receivers and hardware used for despreading, demodulation, channel estimation, and channel decoding.
In addition to monitoring downlink channels over specified time intervals, the UE also performs certain measurement tasks that include but are not limited to searcher tasks. As one example, searcher tasks in wireless technologies are used to detect neighboring cells and determine signal strengths in the serving and neighboring cells, possibly across multiple radio access technologies. While specifications may standardize some timing requirements for the execution of these searcher tasks (e.g., maximum detection/measurement reporting intervals), timing of such measurements made by searcher algorithms at the UE are generally implementation specific. These measurements may be made by the UE on received waveforms/signals while receiver circuitry is on/enabled.
If DRX is configured to be active, then a UE generally ensures that the receiver circuitry (and any other associated circuitry) is enabled during times when the UE monitors downlink channels and also during times when the UE performs searcher tasks. The additional amount of time that searcher tasks require the receiver circuitry to be on/enabled, beyond the amount of time receiver circuitry is required to be on/enabled to monitor downlink channels, may be broadly defined as searcher overhead. Searcher overhead consumes additional energy and may decrease the battery life of the UE. Thus, there is a demand for a way to conserve UE power by reducing searcher overhead.